Error C2059: syntax errors: "constant" solution
Scene
Add Haikang, Yushi SDK docking header file and library file, compilation error prompt error C2059: syntax error: "constant". Display macro definition exception in SDK header file NetDEVSDK.h
Typedef enum tagNETDEV_PASSIVEDECODE_CMD
{
PASSIVE_DEC_PAUSE = 1, / * passive decoding paused (valid only for file streams) * /
PASSIVE_DEC_RESUME = 2, / * resume passive decoding (valid only for file streams) * /
PASSIVE_DEC_FAST = 3, / * Fast passive decoding (valid only for file streams) * /
PASSIVE_DEC_SLOW = 4, / * slow passive decoding (valid only for file streams) * /
PASSIVE_DEC_NORMAL = 5, / * normal passive decoding (valid only for file streams) * /
PASSIVE_DEC_ONEBYONE = 6, / * passive decoding single frame playback (reserved) * /
PASSIVE_DEC_AUDIO_ON = 7, / * Audio on * /
PASSIVE_DEC_AUDIO_OFF = 8, / * Audio off * /
PASSIVE_DEC_RESETBUFFER = 9 / * clear buffer * /
} NETDEV_PASSIVEDECODE_CMD_E
NetDEVSDK.h (5082): error C2059: syntax error: "constant"
NetDEVSDK.h (5091): error C2143: syntax error: missing ";" (before "}")
Mouse over PASSIVE_DEC_PAUSE and see error message: # define PASSIVE_DEC_PAUSE 1
Investigation process
Do a macro definition search PASSIVE_DEC_PAUSE on the entire project directory in Notepad++, and find that HCNetSDK.h has been defined in Haikang's header file.
# define PASSIVE_DEC_PAUSE 1 / * passive decoding paused (valid for file streams only) * /
# define PASSIVE_DEC_RESUME 2 / * resume passive decoding (valid only for file streams) * /
# define PASSIVE_DEC_FAST 3 / * Fast passive decoding (valid only for file streams) * /
# define PASSIVE_DEC_SLOW 4 / * slow passive decoding (valid for file streams only) * /
# define PASSIVE_DEC_NORMAL 5 / * normal passive decoding (valid only for file streams) * /
# define PASSIVE_DEC_ONEBYONE 6 / * passive decoding single frame playback (reserved) * /
# define PASSIVE_DEC_AUDIO_ON 7 / * Audio enabled * /
# define PASSIVE_DEC_AUDIO_OFF 8 / * Audio off * /
# define PASSIVE_DEC_RESETBUFFER 9 / * clear buffer * /
That's why the above prompt error occurred.
Solution
The use of the NETDEV_PASSIVEDECODE_CMD_E macro definition was not found in the SDK header file, so the whole macro definition was commented out directly to solve the problem.
